U.S. patent number 6,433,073 [Application Number 09/626,028] was granted by the patent office on 2002-08-13 for polyurethane dispersion in alcohol-water system.
This patent grant is currently assigned to 3M Innovative Properties Company. Invention is credited to Steven S. Kantner, Kevin M. Lewandowski, Matthew T. Scholz.
United States Patent |
6,433,073 |
Kantner , et al. |
August 13, 2002 |
Polyurethane dispersion in alcohol-water system
Abstract
A polyurethane dispersion and a method of making are provided.
The polyurethane dispersion is stable in a mixture of alcohol and
water. The dispersion comprises the reaction product of (a) an
isocyanate terminated polyurethane prepolymer comprising the
reaction product of (i) at least one oligomeric polyactive hydrogen
compound insoluble in said alcohol, wherein said polyactive
hydrogen compound is an alkyl, aryl, or aralkyl structure
optionally substituted by N, O, and S; (ii) at least one
polyisocyanate, and (iii) at least one polyactive hydrogen compound
soluble in said mixture of alcohol and water; (b) a polyfunctional
chain extender; and (c) a monofunctional chain terminator; wherein
the equivalent ratio of difunctional chain extender to prepolymer
isocyanate is 0.60 to 1.20.
Inventors: |
Kantner; Steven S. (St. Paul,
MN), Scholz; Matthew T. (Woodbury, MN), Lewandowski;
Kevin M. (Inver Grove Heights, MN) |
Assignee: |
3M Innovative Properties
Company (St. Paul, MN)
|
Family
ID: |
24508657 |
Appl.
No.: |
09/626,028 |
Filed: |
July 27, 2000 |
Current U.S.
Class: |
524/591; 424/401;
424/70.1; 528/71; 524/840; 524/839; 424/78.37; 424/70.7; 424/70.11;
424/69; 424/405; 424/61; 424/63; 424/64; 424/59 |
Current CPC
Class: |
A61Q
17/02 (20130101); C08G 18/0819 (20130101); C08G
18/0861 (20130101); A61Q 17/04 (20130101); A61Q
5/12 (20130101); A61Q 5/02 (20130101); A61Q
3/02 (20130101); A61Q 1/08 (20130101); A61Q
19/00 (20130101); C08G 18/0804 (20130101); A61Q
1/06 (20130101); C08G 18/12 (20130101); A61Q
1/02 (20130101); A61K 8/87 (20130101); A61Q
1/10 (20130101); C08G 18/12 (20130101); C08G
18/3228 (20130101); C08G 18/12 (20130101); C08G
18/2825 (20130101) |
Current International
Class: |
A61Q
1/02 (20060101); A61Q 1/08 (20060101); A61Q
3/02 (20060101); A61Q 17/02 (20060101); A61Q
1/10 (20060101); A61Q 1/06 (20060101); A61Q
5/02 (20060101); A61Q 19/00 (20060101); C08G
18/12 (20060101); A61Q 5/12 (20060101); A61K
8/72 (20060101); A61K 8/87 (20060101); C08G
18/00 (20060101); A61Q 17/04 (20060101); C08G
18/08 (20060101); C08J 003/03 (); C08J 003/09 ();
C08G 018/40 (); A61K 007/06 (); A61K 007/043 () |
Field of
Search: |
;524/591,839,840 ;528/71
;424/59,61,63,64,69,70.1,70.7,70.11,78.37,401,405 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
|
0 416 659 |
|
Mar 1991 |
|
EP |
|
656021 |
|
Feb 1994 |
|
EP |
|
0 590 480 |
|
Apr 1994 |
|
EP |
|
938889 |
|
Sep 1999 |
|
EP |
|
WO96/14049 |
|
May 1996 |
|
WO |
|
WO99/43289 |
|
Feb 1999 |
|
WO |
|
Other References
C R. Noller, Chemistry of Organic Compounds, Ch. 6, pp. 121-122
(1957)..
|
Primary Examiner: Sergent; Rabon
Claims
What is claimed is:
1. A polyurethane dispersion stable in a mixture of alcohol and
water, said dispersion comprising the reaction product of: (a) at
least one isocyanate terminated polyurethane prepolymer comprising
the reaction product of (i) at least one polyactive hydrogen
compound insoluble in said alcohol, wherein said polyactive
hydrogen compound is an alkyl, aryl, or aralkyl structure
optionally substituted by N, O or S or combinations thereof in or
on the chain; (ii) at least one polyisocyanate, and (iii) at least
one polyactive hydrogen compound soluble in said mixture of alcohol
and water, (b) at least one polyfunctional chain extender; (c) at
least one chain terminator; and (d) water.
2. The polyurethane dispersion of claim 1, wherein the equivalent
ratio of said chain extender to said prepolymer isocyanate is
0.60:1 to 1: 1.2.
3. The polyurethane dispersion of claim 1, wherein the chain
terminator is monofunctional.
4. The dispersion of claim 1, wherein component (a)(i) is selected
from the group consisting of oligomeric polyols and oligomeric
polyamines having on average from about 1.6 to 4 hydroxyl and/or
amino groups.
5. The dispersion of claim 1, wherein component (a)(i) is selected
from the group consisting of polybutadiene polyols, polyisoprene
polyols, hydrogenated polybutadiene polyols, hydrogenated
polyisoprene polyols, polyester polyols from dimer diacids,
polyester polyols from dimer diols, dimer diols, and combinations
thereof.
6. The dispersion of claim 1 comprising at least 5% by weight of
component (a)(i) based on the total weight of the a(i), a(ii), and
a(iii) components.
7. The dispersion of claim 1, wherein said polyisocyanate is
selected from the group consisting of dicyclohexylmethane
4,4'-diisocyanate;
3,5,5-trimethyl-1-isocyanato-3-isocyanatomethylcyclohexane;
tetramethylene diisocyanate; 1,3-bis(isocyanatomethyl)cyclohexane;
1,3-bis(1-isocyanato-1-methylethyl)benzene; diphenylmethane
4,4'-diisocyanate; 4,4',4"-triisocyanatotriphenylmethane;
polymethylene polyphenylene polyisocyanate; toluene diisocyanate;
hexamethylene diisocyanate; dodecamethylene diisocyanate; m- and
p-xylene diisocyanate, and combinations thereof.
8. The dispersion of claim 1, where component (a)(iii) is selected
from the group consisting of (i) a compound containing an ionic
group, (ii) a compound containing a moiety capable of forming an
ionic group, (iii) a compound containing a polyester, polyether, or
polycarbonate group having a ratio of 5 or less carbon atoms for
each oxygen atom; and (iv) mixtures thereof.
9. The dispersion of claim 8, wherein component (a)(iii) is a
cationic compound having the following structure:
wherein R is C.sub.1 to C.sub.18 alkyl or C.sub.6 to C.sub.18 aryl
or aralkyl optionally substituted in and/or on the chain by N, O or
S or combinations thereof; R.sub.2 is hydrogen or C.sub.1 to
C.sub.18 alkyl; n is an integer from 1 to 200; and X is halogen,
sulfate, methosulfate, ethosulfate, acetate, carbonate, or
phosphate.
10. The dispersion of claim 8, wherein component (a)(iii) is a
compound having the following structure: ##STR2##
wherein each R.sub.1 is independently a divalent aliphatic group
having an average molecular weight of 200 to 600 comprising ether
or ester functional groups selected from the group consisting of
--CH.sub.2 --CH.sub.2 --(OCH.sub.2 --CH.sub.2 --).sub.n --,
--C(CH.sub.3)H--CH.sub.2 --(OC(CH.sub.3)H--CH.sub.2 --).sub.n --,
--(CH.sub.2).sub.4 --(O(CH.sub.2).sub.4).sub.n --,
--(CH.sub.2).sub.m --CO--[--O--(CH.sub.2).sub.m --CO--].sub.n --
groups; and mixtures thereof; where m is an integer from 2 to 5 and
n is an integer from 2 to 15; and M is selected from the group
consisting of Na, H, K, Li, ammonium, methylammonium,
butylammonium, diethylammonium, triethylammonium,
tetraethylammonium, and benzyltrimethyl-ammonium cation.
11. The dispersion of claim 1, wherein said chain extender is
selected from the group consisting of water; ethylenediamine;
1,6-diaminohexane; piperazine; tris(2-aminoethyl)amine; amine
terminated polyethers; adipic acid dihydrazide; oxalic acid
dihydrazide; ethylene glycol; 1,4 butane diol; 1,8 octane diol;
1,2-ethanedithiol; 1,4-butanedithiol; 2,2'-oxytris(ethane thiol);
and di- and tri-mercaptopropionate esters of poly(oxyethylene)
diols and triols.
12. The dispersion of claim 1, wherein said polyurethane dispersion
has an ionic content of about 1000 to 15000 gram of prepolymer per
equivalent of ionic group.
13. The dispersion of claim 1, wherein said reaction product has a
weight average molecular weight of about 5000 to 50000.
14. The dispersion of claim 1, wherein said dispersion further
comprises a lower alcohol.
15. The dispersion of claim 14, wherein said lower alcohol is
selected from the group consisting of ethanol, n-propanol,
2-propanol, and combinations thereof.
16. The dispersion of claim 14, wherein said composition comprises
at least 20% by weight of said lower alcohol based on the total
composition weight.
17. A cold seal adhesive comprising the dispersion of claim 1.
18. The adhesive of claim 17 exhibiting self-adhesion properties
when coated and dried to a film of about 0.025 millimeter in
thickness.
19. The adhesive of claim 17 having an adhesion to self value
greater than 5 Newtons per decimeter.
20. The adhesive of claim 17 having an adhesion to glass value less
than 10 Newtons per decimeter.
21. A product comprising the dispersion of claim 1, the product
selected from the group consisting of self-seal envelopes, bundling
tapes, heat sensitive products, containers, text binders, medical
products, packaging material for medical products, and diaper
closures.
22. A saturant in a cohesive elastomeric bandage compring the
dispersion of claim 1.
23. A cosmetic application comprising the dispersion of claim 1,
the cosmetic application selected from the group consisting of
mascara, foundation, rouge, face powder, eye liner, eye shadow,
lipstick, insect repellent, nail polish, skin moisturizer, skin
cream, body lotion, and sunscreen.
24. A hair care composition comprising the dispersion of claim 1,
the hair care composition selected from the group consisting of
shampoos, conditioners, hair sprays, mousses, and gels and wherein
said hair care composition is not a resphapeable hair styling
composition.
25. The dispersion of claim 1 further comprising an additive
selected from the group consisting of defoaming agents, flow and
leveling agents, rheology modifiers, photostabilizers, and
combinations thereof.
26. A polyurethane dispersion stable in a mixture of alcohol and
water, said dispersion comprising the reaction product of: (a) an
isocyanate terminated polyurethane prepolymer comprising the
reaction product of (i) about 20 to 30 parts by weight hydrogenated
polybutadiene diol, (ii) about 15 to 30 parts by weight isophorone
diisocyanate, and (iii) about 0 to 10 parts by weight sulfonated
polyester diol and about 25 to 75 parts by weight
polytetramethylene oxide diol; (b) about 0.05 to 5 parts by weight
ethylene diamine; (c) about 0 to 5 parts by weight
2-amino-2-methyl-1-propanol; and (d) water.
Description
TECHNICAL FIELD
The present invention pertains to a cold seal adhesive composition
in the form of a stable polyurethane dispersion in alcohol-water
system.
BACKGROUND
Polyurethane is a generic term used to describe polymers prepared
by the reaction of a polyfunctional isocyanate with a
polyfunctional alcohol to form urethane linkages. The term
"polyurethane" has also been used more generically to refer to the
reaction products of polyisocyanates with any polyactive hydrogen
compound including polyfunctional alcohols, amines, and mercaptans.
Polyurethanes are used in a variety of applications including as
elastomers, adhesives, coatings, and impregnating agents.
For coating applications, polyurethane polymers can be dispersed in
water by incorporating stabilizing groups into their backbone.
Anionic, cationic, and non-ionic dispersion stabilizing groups have
been used. Various aqueous polyurethane dispersions have been
prepared by those skilled in the art. For example, U.S. Pat. No.
3,479,310 (Dieterich et al.) discloses water-dispersed polyurethane
polymers suitable for use as waterproof coatings. The polymer is
prepared from polyhydroxy compounds, polyisocyanates, optional
chain lengthening agents, and a sufficient amount of a component
having an ionic salt-type group. U.S. Pat. No. 4,307,219 (Larson)
discloses water dispersible polyurethane resin prepared by reaction
of hydrophilic diols, hydrophobic diols, diisocyanates, and,
optionally, chain extenders. Such a urethane resin can be used as
protective coatings, primers, and binders.
Although aqueous dispersions of polyurethanes have been widely
disclosed, the inventors are not aware of any references to stable
polyurethane dispersions in alcohol-water solvent systems,
particularly in the absence of hydrophilic stabilizing moieties.
Stable polyurethane dispersions in hydro-alcohol (i.e.,
alcohol-water) systems are especially difficult for at least two
reasons.
First, the addition of lower alcohols (e.g., C.sub.1 to C.sub.4) to
water decreases the surface tension of the solvent system. For
example, a 40% by weight ethanol in water system has a surface
tension of about 31 dyne/cm compared to a pure water system, which
has a surface tension of about 72 dyne/cm at about 20.degree. C. A
60% by weight ethanol in water system has a surface tension of 27
dyne/cm at about 20.degree. C. The reduction in surface tension can
affect the ability to self assemble hydrophilic and hydrophobic
domains during the dispersion preparation. Secondly, many of the
polyurethane components (i.e., the starting reactants) are soluble
in hydro-alcohol solvent systems, which result in solutions and not
dispersions. Polymer solutions have substantially higher viscosity
than polymer dispersions, making the solutions harder to process in
certain operations, such as coating and spraying operations.
Polymer solutions also tend to achieve lower percent solids when
compared to polymer dispersions, making the former less attractive
during coating operations and during shipping. Lower solids
solutions also require longer drying times than dispersions both
because of the greater amount of solvent present and the higher
affinity of the polymer for that solvent. Furthermore, the
molecular weight of soluble polymers is often much lower than that
of dispersions.
U.S. Pat. No. 4,507,430 (Shimada et al.) discloses a water-based
polyurethane emulsion that comprises a hydrogenated polyalkadiene
polyol component and a polyisocyanate component. Shimada discloses
that the materials are useful as an adhesive or coating material
for a polyolefin resin, and can be applied wet and dried or bonded
by dry lamination requiring heat and pressure. There was no
disclosure of polyurethane dispersions in hydro-alcohol solvent
system.
U.S. Pat. No. Re. 34,730 (Salatin et al.) discloses waterborne
basecoat compositions comprising (a) an anionic polyurethane resin
comprised of (i) a polyester resin component produced by reaction
of a carboxylic acid component comprised of at least 50% by weight
C.sub.18-60 long chain acid and a polyol and (ii) a mixture of at
least one multifunctional compound having at least one active
hydrogen functionality and at least one carboxylic acid
functionality neutralized with an amine, (b) a polyisocyanate
combined with a crosslinking agent, and (c) a rheology control
agent. U.S. Pat. No. 5,326,815 (Serdiuk et al.) discloses a coating
composition comprising (a) an aqueous medium, (b) a
water-dispersible polyurethane resin that is the reaction product
of (i) a hydroxy-functional polyester resin component that is the
reaction product of a carboxylic acid component comprising at least
two carboxylic acids, a C.sub.36 dimer fatty alcohol, and a
short-chain polyol, (ii) a multifunctional compound having at least
one active hydrogen group and at least one water-stabilizing group,
(iii) an active hydrogen-containing capping or chain extending
agent, and (iv) a polyisocyanate, and (c) an aminoplast
crosslinking agent. The active hydrogen-containing capping agent is
used in excess to terminate the isocyanate functional prepolymer,
providing terminal hydroxyl groups for reaction with the
crosslinking agent. Other patents describing the use of dimer fatty
alcohols or polyesters derived from dimer acid in waterbased
polyurethane dispersions for basecoat compositions include U.S.
Pat. No. 4,423,179 (Guagliardo), U.S. Pat. No. 5,334,650 (Serdiuk
et al.), and U.S. Pat. No. 5,370,910 (Hille et al.). None of the
above references disclose a polyurethane dispersion in
alcohol-water system.
U.S. Pat. No. 5,672,653 (Frisch et al.) discloses an anionic
waterborne polyurethane dispersion prepared by (a) forming a
prepolymer from hydroxy terminated polybutadiene resin, an
aliphatic isocyanate, and a diol containing acid groups; (b)
neutralizing the acid; dispersing it in water; and (c) chain
extending the prepolymer with a diamine.
Cold seal properties in adhesives have been discussed by those
skilled in the art. For example, U.S. Pat. No. 5,616,400 (Zhang)
discloses a sheet material coated with a dry cold seal adhesive
consisting essentially of the reaction product of 50 to 80%
polyester polyol, 15-25% aliphatic diisocyanate, and 3 to 6%
dimethylol propionic acid neutralized with a base, said reaction
product having a T.sub.g between about -20.degree. and 5.degree. C.
U.S. Pat. No. 5,981,650 (Zhao et al.) discloses an aqueous
cold-seal adhesive dispersion containing 30% to 55% of a
polyurethane ionomer with a T.sub.g between -50.degree. C. and
10.degree. C., which is the reaction product of a polyester polyol
and polyether polyol blend, an aliphatic diisocyanate, and
dimethylol propionic acid, with 0.05% to 4% colloidal amorphous
silica reacted in situ with an organic NCO containing moiety. The
use of an alcohol insoluble oligomeric diol is not disclosed in
these patents, nor is the importance of controlling molecular
weight through the use of chain terminators to give cold seal
adhesive properties.
Water-soluble or water-dispersible polyurethanes have been
disclosed for use in cosmetic formulations. EP 656,021 B1 (Son et
al.), WO 96/14049 (Emmerling et al.), U.S. Pat. No. 5,643,581
(Mougin et al.), U.S. Pat. No. 5,874,072 (Alwattari et al.), U.S.
Pat. No. 5,972,354 (de la Poterie et al.), WO 99/43289 (Ohta et
al.), EP 938,889 A2 (Son et al.), and U.S. Pat. No. 5,968,494
(Kukkala et al.) are representative. None use oligomeric alcohol
insoluble polyactive hydrogen compounds, such as oligomeric alcohol
insoluble diols, in preparing the polyurethane.
None of the technologies discussed above recognize the importance
of controlling molecular weight through the use of chain
terminators to give cold seal adhesive properties, nor do they
suggest the use of these materials in cosmetic or medical
formulations.
A need exists in the art for polyurethane dispersions stable in
alcohol-water solvent systems, where the dispersion has one or more
of the following properties: capable of forming stable dispersions
in hydro-alcohol systems, capable of rapidly forming films on skin
or hair by simple ambient evaporation, and capable of achieving
high solids level. Furthermore, films formed by drying down the
dispersions exhibit one or more of the following properties: high
self adhesion and yet low tack, low humidity sensitivity, and high
tensile strength.
SUMMARY
The present invention provides a novel polyurethane-urea dispersion
that can be prepared in the presence of and is dispersed in a
hydro-alcohol system. As used herein, the term "hydro-alcohol"
refers to solvents based on C.sub.1 to C.sub.4 lower alcohols mixed
with water, wherein the weight ratio of lower alcohol to water is
preferably at least 20:80, more preferably at least 40:60, even
more preferably at least 60:40 and most preferably at least 70:30
by weight. The preferred lower alcohols include ethanol,
2-propanol, and n-propanol. The term "hydro-alcohol" is synonymous
with the term "alcohol-water."
As used herein, "dispersion" means generally a two phase system
where one phase contains discrete particles distributed throughout
a bulk substance, the particles being the disperse or internal
phase, and the bulk substance the continuous or external phase. In
this invention, the continuous phase is the alcohol-water mixture
and at least a portion of the polyurethane exists as the discrete
particle. By "dispersion," it is also meant that not necessarily
the entire polyurethane polymer needs to be alcohol-water
insoluble; some of the polymer can be soluble in the alcohol-water
mixture. Dispersions are possible through the use of certain
components that are insoluble in the solvent system. It is
desirable that the dispersion remains stable under ambient
conditions. Preferred dispersions are stable at room temperature
for more than 30 days, preferably more than 90 days, more
preferably for more than 180 days, and most preferably for more
than 360 days.
In one aspect of the present invention, the molecular weight of the
polyurethane polymer is deliberately limited to produce a material
that, when coated onto a substrate, forms a film with high cohesive
strength, i.e., the adhesion of the film to itself is high.
Furthermore, many of these novel formulations have very low
adhesion to other surfaces, such as glass.
In brief summary, in one aspect, the invention provides a
polyurethane dispersion stable in a mixture of alcohol and water,
the dispersion comprising the reaction product of: (a) an
isocyanate terminated polyurethane prepolymer comprising the
reaction product of (i) at least one polyactive hydrogen compound
insoluble in the alcohol, wherein the polyactive hydrogen compound
is an alkyl, aryl, or aralkyl structure optionally substituted by
N, O, S and combinations thereof (referred to as the "A" component
for convenience); (ii) at least one polyisocyanate, and (iii) at
least one polyactive hydrogen compound soluble in the mixture of
alcohol and water (referred to as the "B" component for
convenience); (b) a polyfunctional chain extender; and (c) a chain
terminator. In one embodiment, the equivalent ratio of active
hydrogen on the chain extender to the prepolymer isocyanate is
0.6:1 to 1.20:1. In another embodiment, the chain terminator is a
monofunctional hydroxy or amine.
In a preferred embodiment, the inventive polyurethane dispersion is
stable in a mixture of alcohol and water and the dispersion
comprises the reaction product of (a) an isocyanate terminated
polyurethane prepolymer comprising the reaction product of (i)
about 20 to 30 parts by weight hydrogenated polybutadiene diol,
(ii) about 15 to 30 parts by weight isophorone diisocyanate, and
(iii) about 0 to 10 parts by weight sulfonated polyester diol and
(iv) about 25 to 75 parts by weight polytetramethylene oxide diol;
(b) about 0.05 to 5 parts by weight ethylene diamine; and (c) about
0 to 5 parts by weight 2-amino-2-methyl-1-propanol.
In yet another embodiment, the inventive polyurethane dispersion is
useful as a cold seal adhesive. As used herein, the term "cold seal
adhesive" (commonly referred to as "contact adhesive") means the
adhesive exhibits good self adhesion properties and is typically
non-adhering or only very slightly adhering to chemically
dissimilar surfaces at temperatures of about 15.degree. to
50.degree. C. When placed against each other, cold seal adhesives
typically require moderate pressure (such as exerted by fingertip
pressure) to achieve a bond without the need to use significantly
elevated temperatures. That is, a bond may be formed at room
temperature (i.e., about 20.degree. to 30.degree. C.) and even
lower temperature (e.g., about 15.degree. C.), as well as at
temperatures up to about 50.degree. C. Thermal curing or
crosslinking agents are typically not needed for the cold seal
adhesive to form a bond.
As used herein, a material possesses "self adhesion" properties
when it preferentially adheres to itself or a chemically similar
material under pressure or force without the need for significantly
elevated temperatures (e.g., without the need for temperatures
above about 50.degree. C.). Preferred compositions of the invention
exhibit self adhesion properties immediately upon contact to itself
at room temperature (about 20.degree. to 30.degree. C.). As used in
the previous sentence, the term "immediately" means less than a few
minutes, e.g., about 5 minutes, preferably less than 1 minute, more
preferably less than 30 seconds, depending on the application.
A cold seal adhesive is to be distinguished from a pressure
sensitive adhesive (PSA). A PSA typically has tack at room
temperature, requires moderate pressure to achieve a bond (such as
that exerted by fingertip pressure), and adheres to a wide variety
of dissimilar substrates. A PSA is conventionally understood to
refer to an adhesive that displays permanent and aggressive tack to
a wide variety of substrates after applying moderate pressure. An
accepted quantitative description of a PSA is given by the
Dahlquist criterion line, which indicates that materials having a
storage modulus (G') of less than about 3.times.10.sup.5 Pascals
(measured at 10 radians/second at a temperature of about 20.degree.
to 22.degree. C.) have PSA properties while materials having a G'
in excess of this value do not.
The inventive polyurethane dispersions are useful in a variety of
applications where cold seal properties are desirable. Such
applications include the manufacture of self-seal envelopes; in
food packaging applications were heat should be avoided (especially
ice cream, sugar cubes, tea bags, baked goods, snacks, milk and
dairy products, dried and frozen foods, chocolates and other
candies, meats, beverages, condiments/spices, sauces and pet
foods); in sealing cartons, bags, and other containers; in bundling
tapes; in book binding; in cigarette and detergent packaging;
liquid packaging; and twist wraps, medical packaging articles, and
adhering medical articles to skin.
An advantage of the inventive composition is the use of an
oligomeric alcohol insoluble polyactive hydrogen compound. Because
of its hydrophobic nature, such compound provides faster drying and
improved hydrolytic stability over prior art synthetic cold seal
adhesives. A further advantage of the inventive composition is that
it possesses adhesion to low energy substrates similar to that
provided by natural rubber-based cold seal adhesives, but without
the disadvantages associated with such adhesives. Those
disadvantages include discoloration, unpleasant odor, undesirable
foaming in wet form, hypersensitivity, and possibility of
anaphylactic shock due to the presence of natural latex
proteins.
Yet another advantage of the inventive composition is that it has
low viscosity and fast drying characteristics in addition to
exhibiting self adhesion properties. Thus, the composition is
suitable for use as a saturant in processes for preparing cohesive
elastomeric bandages such as disclosed in U.S. Pat. No. 4,699,133
(Schafer et al.); U.S. Pat. No. 5,230,701 (Meyer et al.); U.S. Pat.
No. 5,692,937 (Zhang); and U.S. Pat. No. 5,843,523 (Mazza et al.);
all incorporated herein by reference.
A further advantage of the inventive composition is its ability to
form hydrophobic films making it useful in cosmetic applications.
Such applications require some amount of water resistance, transfer
resistance, or substantivity to skin, nails or hair. The
applications include, e.g., makeup cosmetic or protective cosmetic
applications such as mascara, foundation, rouge, face powder,
eyeliner, eyeshadow, insect repellent, nail polish, skin
moisturizer, skin cream and body lotion, lipstick, and
sunscreen.
When the inventive dispersion is used in hair care products, such
as shampoos and conditioners and the like, the dispersion can
provide faster drying. It can also improve the humidity resistance
of hair styling agents when used at low levels in combination with
other hair styling resins. The hair care products, as described
herein, are not "reshapable" hair styling compositions.
"Reshapable" hair styling composition means a composition that can
be restored or modified without new material or heat being applied.
For example, in order to restore or modify the hairstyle in case of
"drooping" or loss of setting (dishevelment), no new materials,
such as water or any form of fixing agent, or heat are required.
The composition can be long lasting, such as 10 to 24 hours, giving
rise to a durable styling effect.
In the medical article applications, the skin may be coated with
the inventive polyurethane dispersion and allowed to dry to form a
film. A medical article also pre-coated with the inventive
dispersion may be attached to the film. It is a significant
advantage that the inventive composition may be adhered to skin and
would not have to be removed repeatedly in applications such as
ostomy or wound dressing to prevent skin stripping. The adhesives
made from the inventive polyurethane dispersions can also be used
in any application where ambient temperature self-sealing is
required.
DETAILED DESCRIPTION OF THE INVENTION
In brief summary, the dispersion is made by forming the isocyanate
terminated polyurethane prepolymer, chain extending the prepolymer,
and chain terminating the prepolymer to yield a polyurethane
polymer that is stable and dispersed in an alcohol-water solvent
system. Although it is presently preferred to carry out the
foregoing steps sequentially, this is not necessary. The order of
the steps may be changed and certain steps can be combined, such as
chain extension and chain termination or prepolymer formation and
chain termination, etc. The steps and the components necessary to
carry them out are discussed in detail below. In use, the
dispersion is typically coated onto a substrate, such as a liner,
dried and cured to form a film.
As used herein the term "isocyanate terminated polyurethane
prepolymer" (alternately referred to as "isocyanate functional
polyurethane prepolymer") means a reaction product of at least one
polyisocyanate and at least one polyactive hydrogen compound (i.e.,
polyol). In general, the reaction occurs with a molar excess of
isocyanate groups to produce an oligomer, which may have urethane,
urea, thiourethane functional groups and combinations thereof. The
prepolymer can be prepared at an equivalent ratio of isocyanate
groups to active hydrogen reactive groups of greater than 1.6,
preferably greater than 1.8, and most preferably about 2.0 or
greater.
As used herein, a "polyol" includes compounds containing active
hydrogen in accordance with the Zerevitanov test described by C. R.
Noller, Chemistry of Organic Compounds, Chapter 6, pages 121-22
(1957). The term "polyol" further means a compound having an
average functionality greater than 1, preferably greater than 1.8,
and most preferably about 2.0 or greater but less than about 6,
preferably less than about 4, and most preferably about 3 or less.
It is understood to include compounds that have (i) alcohol groups
on primary, secondary, and tertiary carbon atoms, (ii) primary and
secondary amines, (iii) mercaptans, and (iv) mixtures of these
functional groups. Accordingly, the inventive polyurethane
dispersions can contain urea linkages, e.g., from the reaction of
isocyanate functional polyurethanes with amines, these polymers
more appropriately being labeled as "polyurethane-ureas." Polyols
useful for preparing the prepolymer have a molecular weight of 62
to 10,000, preferably 200 to 5,000, and most preferably from 400 to
3,000.
The "A" component, is preferably present at concentrations of at
least 5%, preferably at least 10%, and most preferably at least 20%
by weight, based on the total weight of the "A" component, the
polyisocyanate, and the "B" component. The latter two components
are discussed in detail below. The "A" component is insoluble in
the alcohol of the alcohol-water mixture used to form the
dispersion. The phrase "insoluble" means generally that at least 1
gram of the compound is not soluble in about 4 grams of alcohol at
about 25.degree. C. Certain polyols may require heating to melt to
determine whether they or insoluble using this characterization
method.
The polyols suitable for use as the "A" component have an alkyl,
aryl, or aralkyl structure optionally substituted by N, O, S and
combinations thereof in and/or on the chain. The "A" component has
a number average molecular weight preferably above about 300, more
preferably above about 400, and most preferably above about 500,
but preferably below about 10000, more preferably below about 5000
and most preferably below about 3000.
Monomeric polyols, such as the C.sub.36 dimer fatty alcohol
available as PRIPOL 2033 from Uniqema North America, Chicago, Ill.,
USA, can be used. Oligomeric polyols having, on average, from about
1.6 to about 4 hydroxyl or amino groups are preferred. One type of
preferred oligomeric polyol useful as the "A" component is
aliphatic polyester polyol based on diacids and/or diols that have
greater than 10 carbon atoms and preferably greater than 20 carbon
atoms. Commercially preferred polyester polyols are PRIPLAST 3191,
3192, 3196, 3197, 1906, and 1907 from Uniqema North America,
Chicago, Ill., USA, which are believed to be based on 36 carbon
atom diacid and/or diol. Specific constituents used in preparation
of these diols are believed to be: for PRIPLAST 3192--dimer acid,
adipic acid, and 1,6-hexane diol; for PRIPLAST 3193--dimer acid and
ethylene glycol; for PRIPLAST 3194--dimer acid, adipic acid, and
ethylene glycol; for PRIPLAST 3196--dimer acid and 1,6-hexane diol;
for PRIPLAST 3197--dimer acid and dimer diol; for PRIPLAST
1906--isophthalic acid and dimer diol; and for PRIPLAST
1907--terephthalic acid and dimer diol. The term "dimer acid" is
understood to be a C.sub.36 diacid formed by dimerization of
unsatured C.sub.18 fatty acids. The term "dimer diol" is understood
to be a C.sub.36 difunctional polyol formed by hydrogenation of the
C.sub.36 dimer acid. Another preferred oligomeric polyol is hydroxy
terminated polyalkadienes including polybutadienes and
polyisoprenes. A commercially preferred hydroxy terminated
polybutadiene is POLY bd resin from Elf Atochem North America,
Philadelphia, Pa., USA.
Yet another preferred oligomeric polyol is hydrogenated
polyalkadiene polyols including hydrogenated polyisoprene and
hydrogenated polybutadiene, the latter having no less than 19% by
weight 1,2-butadiene addition. Commercially preferred hydrogenated
polybutadiene diols include KRATON L2203 from Shell Chemical,
Houston, Tex., USA and POLYTAIL resins from Mitsubishi Chemical,
Tokyo, Japan. A preferred type of oligomeric polyamine is amine
terminated butadiene polymers and butadiene-acrylonitrile
copolymers. A commercially preferred amine is HYCAR ATBN from B.F.
Goodrich, Cleveland, Ohio., USA.
Silicone polyols and perfluoroalkyl functional polyols, when used,
preferably should not be present in greater than about 5 weight
percentage of the overall composition as their low surface energy
properties would be expected to detract from the desired adhesion
characteristics based on the teachings of U.S. Pat. No. 5,679,754
(Larson et al.).
In addition to alcohol insoluble polyols, low molecular weight
"monomeric" polyols may be used to form the prepolymer. Examples of
the monomeric polyols include ethylene glycol, propylene glycol,
butylene glycol, hexamethylene glycol, diethylene glycol,
1,1,1-trimethylolpropane, pentaerythritol, aminoethanol, and the
like. When used, preferably the amount of the monomeric polyols
should be kept low to minimize the viscosity of the prepolymer.
The amounts of the polyol and isocyanate used to form the
prepolymer affects the physical and chemical properties of the
final polymer. Properties that can be varied include, but are not
limited to, ductility, water uptake, tensile strength, modulus,
abrasion resistance, minimum film-forming temperature, glass
transition temperature, ultraviolet light resistance, and
resistance to hydrolysis and color stability. In general, longer
chain polyols tend to provide films made from the dispersions that
are more ductile and have lower T.sub.g, higher elongation, and
lower tensile strength. In contrast, shorter chain polyols tend to
provide films that have high modulus, greater tensile strength, and
higher T.sub.g. Aliphatic polyols tend to provide materials with
decreased water uptake whereas diols containing heteroatoms in the
backbone (e.g., polyether polyols) tend to have increased water
uptake. The amount of water left in the film can affect its tensile
and elongation properties. When resistance to hydrolysis is
important, polyols should be selected that are hydrolytically
stable such as polyether and polysiloxane polyols, and polyols
based on polyolefin backbones. Polyester polyols may be used that
are hydrolytically resistant such as those based on hydrophobic
subunits (PRIPLAST polyols from Uniqema), those based on
isophthalic acid, as well as polycaprolactone polyols.
Representative polyisocyanates that can be used to form the
isocyanate functional polyurethane include aliphatic and aromatic
polyisocyanates. Suitable polyisocyanates are preferably aliphatic
or cycloaliphatic isocyanates. The aromatic isocyanates are less
preferred as they tend to discolor in ultraviolet light making them
undesirable in outdoor applications. Particularly preferred
diisocyanates include dicyclohexylmethane 4,4'-diisocyanate
(commonly referred to as H.sub.12 MDI) and
3,5,5-trimethyl-1-isocyanato-3-isocyanatomethylcyclohexane
(commonly referred to as isophorone diisocyanate or IPDI), both
available from Bayer Corp., Pittsburgh, Pa., USA, under the trade
designations DESMODUR W and DESMODUR I, respectively. Other
preferred diisocyanates include (i) tetramethylene diisocyanate,
(ii) 1,3-bis(isocyanatomethyl)cyclohexane, (iii)
1,3-bis(1-isocyanato-1-methylethyl)benzene, (iv) diphenylmethane
4,4'-diisocyanate (commonly referred to as MDI), (v) 4,4',
4"-triisocyanatotriphenylmethane, (vi) polymethylene polyphenylene
polyisocyanate (commonly referred to as polymeric MDI), (vii)
toluene diisocyanate (commonly referred to as TDI), (viii)
hexamethylene diisocyanate (commonly referred to as HDI), (ix)
dodecamethylene diisocyanate, and (x) m- and p-xylene
diisocyanate.
Other useful polyisocyanates include those described in U.S. Pat.
No. 3,700,643 (Smith et al.) and U.S. Pat. No. 3,600,359 (Miranda),
which are incorporated herein by reference. Mixtures of
polyisocyanates can also be used, such as ISONATE 2143L, available
from Dow Chemical Co., Midland, Mich., USA.
The polyurethane prepolymer is made alcohol-water dispersible by
using a "B" component having at least one alcohol-water soluble
polyactive hydrogen compound. That is, the "B" component acts
primarily to stabilize the polyurethane dispersion in a water or
alcohol-water solvent system. The phrase "alcohol-water soluble"
means generally that at least 1 gram of the compound is soluble in
about 4 grams of an alcohol-water mixture at about 25.degree. C.
Certain compounds may require heating to melt to determine whether
they are soluble using this characterization method. The
alcohol-water mixture used in this characterization method should
be the same alcohol-water mixture used to prepare the hydro-alcohol
dispersing medium. Alcohol-water solubility is imparted to this
compound by the presence of an ionic group, a moiety capable of
forming an ionic group, or a polyester, polyether, or polycarbonate
group having a ratio of 5 or less, preferably 4 or less, carbon
atoms for each oxygen atom, and mixtures thereof.
When present, the ionic group of the "B" component can be anionic,
cationic, or zwitterionic. The cationic groups may originate from
the isocyanate or polyol component but most conveniently are added
in as a polyol component. The cationic group may be incorporated
directly into the prepolymer. For example, a quaternary diol such
as VARIQUAT 1215 may be reacted into the prepolymer directly.
Alternatively, a precursor group can be reacted into the prepolymer
and then be rendered cationic in a subsequent reaction. For
example, active hydrogen functional tertiary amines such as
methyldiethanolamine and its polyethoxylated adducts may be
incorporated into the prepolymer backbone and subsequently
protonated with a mineral or organic acid to form an ionic salt or
alkylated to form a quaternary ammonium group. Reaction of the
incorporated tertiary amine with hydrogen peroxide, propane sultone
or lactone gives zwitterionic moieties. Preferred stabilizing
cationic components are very water soluble, generally have a
solubility in water of at least 1% by weight and preferably in
excess of 10% by weight. Preferred stabilizing cationic compounds
have the following structure:
where R is C.sub.1 to C.sub.18 alkyl or C.sub.6 to C.sub.18 aryl or
aralkyl optionally substituted in and/or on the chain by N,O, S,
and combinations thereof; R.sub.2 is hydrogen or C.sub.1 to
C.sub.18 alkyl; n is an integer from about 1 to 200, preferably 1
to 50, and most preferably 1 to 20; and X is halogen, sulfate,
methosulfate, ethosulfate, acetate, carbonate, or phosphate.
Preferred cationic stabilizing compounds include protonated and
alkylated methyl diethanol amine as well as PEG 2 cocomonium
chloride and PEG-15 cocomonium chloride available from CK Witco,
Greenwich, Conn., USA as VARIQUAT 638 and VARIQUAT K1215
respectively.
It is possible to incorporate cationic compounds that have a single
reactive hydrogen group. However, they are less preferred.
The anionic stabilizer used in the present invention can be present
on either the isocyanate component or the polyol component.
Typically, and most conveniently, the anionic stabilizer is present
as the polyol component. The anionic group can be sulfonate,
phosphonate, phosphate, and carboxylate but is preferably either
sulfonate or carboxylate and most preferably a sulfonate. The most
preferred sulfonates are the sulfonated polyols described in U.S.
Pat. No. 4,738,992 (Larson et al.). Particularly preferred
sulfonates are polyesterdiols having the following structure:
##STR1##
wherein each R.sub.1 is independently a divalent aliphatic group
having an average molecular weight of 200 to 600 comprising ether
or ester functional groups selected from the group consisting of
poly (C.sub.2 to C.sub.4 alkylene oxide), preferably: --CH.sub.2
--CH.sub.2 --(OCH.sub.2 --CH.sub.2 --).sub.n --, --C(CH.sub.3
)H--CH.sub.2 --(OC(CH.sub.3)H--CH.sub.2 --).sub.n --,
--(CH.sub.2).sub.4 --(O(CH.sub.2).sub.4).sub.n --,
--(CH.sub.2).sub.m --CO--[--O--(CH.sub.2).sub.m --CO--].sub.n
--groups, and mixtures thereof, where m is an integer from about 2
to 5 and n is an integer from about 2 to 15, and M is a cation,
preferably M is Na, but M can be H, K, Li, or a primary, secondary,
tertiary, or quaternary ammonium cation such as ammonium,
methylammonium, butylammonium, diethylammonium, triethylammonium,
tetraethylammonium, and benzyltrimethyl-ammonium cation.
Suitable carboxylate and carboxylic acid functional polyols include
dimethylolpropionic acid and its polyethoxylated derivatives as
well as acid grafted polyethers such as the UCARMOD polyols
available from Union Carbide Specialty Chemicals Div., Danbury,
Conn., USA. These can be neutralized with an organic or inorganic
base either before or after preparation of the prepolymer.
To obtain alcohol-water or water dispersibility, the ionic
equivalent weight of the prepolymer (grams prepolymer per
equivalent of ionic functionality) should be in the range of 1000
to 15000, preferably 1500 to 12500, more preferably 2000 to 10000,
most preferably 2500 to 7500.
Examples of oligomeric polyols that have sufficient polar non-ionic
groups such as ether or ester functionality that provides a ratio
of 5 or less carbon atoms for each oxygen atom to give
alcohol-water solubility include (i) polyoxyalkylene diols, triols,
and tetrols, (ii) polyoxyalkylene diamines and triamines, (iii)
polyester diols, triols, and tetrols of organic polycarboxylic
acids and polyhydric alcohols, and (iv) polylactone diols, triols,
and tetrols having a molecular weight of 106 to about 2000.
Preferred oligomeric polyols and polyamines include (i)
polyethylene oxide homopolymers (e.g., CARBOWAX series from Union
Carbide, Danbury, Conn., USA), block copolymers of ethylene oxide
and propylene oxide (e.g., PLURONIC surfactants from BASF
Corporation, Mount Olive, N.J., USA), random copolymers of ethylene
oxide and propylene oxide (e.g., UCON FLUIDS from Union Carbide,
Danbury, Conn., USA), silicone copolyols, as well as surfactants
based on polyethylene oxide as described in U.S. Pat. No. 4,667,661
(Scholz et al.), (ii) polyoxypropylene diols and triols such as the
ACCLAIM series of polyols from Arco Chemical, Newtown Square, Pa.,
USA, (iii) polyether diamines and triamines such as the JEFFAMINE
series available from Huntsman Corporation, Salt Lake City, Utah.,
USA, (iv) polyether polyols such as the TERATHANE series (which is
a polyoxytetramethylene diol) available from E. I. du Pont Co.,
Wilmington, Del., USA, and the POLYMEG series available from Quaker
Oats Co., Chicago, Ill., USA, (v) polyester polyols such as
MULTRON, which is a poly(ethyleneadipate)polyol, available from
Bayer Corporation, Pittsburgh, Pa., USA, (vi) polycarbonate diols
such as those available from Stahl USA Co., Peabody, Mass., USA,
and (vii) polycaprolactone polyols such as the TONE series
available from Union Carbide, Danbury, Conn., USA. Polythioether
polyols are also useful.
The reaction of the components discussed above (i.e., the "A"
component, the polyisocyanate, and the "B" component) to form the
prepolymer will depend on their selection. Aromatic isocyanates are
generally much more reactive than aliphatic isocyanates and may be
reacted with polyols without the need for heat because the reaction
will be exothermic. The reaction may be run as 100% solids (i.e.,
little to no solvent) or may be carried out in an optionally polar
organic solvent unreactive with the isocyanate. Such solvents
include, for example, acetone, methyl ethyl ketone (MEK),
methoxypropanol acetate (PM acetate), dimethyl acetamide,
tetrahydrofuran, N-methyl-pyrrolidinone and mixtures thereof.
Preferably, the solvent used will not require removal in the final
composition. It is also possible to incorporate solvents and/or
plasticizers that are left in the prepolymer that become part of
the finished dispersion.
When using preferred aliphatic isocyanates with polyfunctional
alcohols, high solids concentrations and elevated reaction
temperatures from about 50.degree. C. to 80.degree. C. are
desirable so that high conversions of monomers to polymer can occur
in a reasonable time, e.g., less than eight hours, preferably less
than three hours. Preferred embodiments incorporating isophorone
diisocyanate or hexamethylene diisocyanate and aliphatic primary or
secondary alcohols are typically heated to about 80.degree. C. for
about 2 hours in the presence of a small amount of catalyst.
Useful catalysts include metal salts such as dibutyltin dilaurate
and dibutyltin diacetate, and amines, such as triethylamine, DBU
(1,8-diazabicyclo[5.4.0]undec-7-ene), and DABCO
(1,4-diazabicyclo[2.2.2]octane), in useful concentrations of from
about 0.01 to 1.0 mole percent (relative to the isocyanate
reagent). Preferred catalysts are non-irritating and
non-sensitizing to skin. Most preferred catalysts are those that
can become bound to the polymer backbone and are thus
non-leachable, such as FASTCAT 4224 from Elf Atochem North America,
Philadelphia, Pa., USA and certain alcohol and amine functional
tertiary amine catalysts such as methyldiethanolamine and
tetramethylguanidine. In batch preparations from about 100 to 1000
grams, we have typically used about 0.1 gram of FASTCAT 4224 per
100 gram of total resin.
The ratio of polyisocyanate to polyol is adjusted such that the
prepolymer has a molecular weight of about 1000 to 25000. The
equivalents of polyisocyanate preferably exceed the total
equivalents of polyol (i.e., total equivalents of active hydrogen),
the equivalent excess being preferably from about 1. 1:1 to 6:1,
more preferably about 1.5:1 to 3:1, and most preferably about 1.8:1
to 2.2:1.
Once the prepolymer is formed, the molecular weight should be
increased to yield a composition with the desired properties. This
step is accomplished by reacting the prepolymer with a "chain
extender." As used herein the term "chain extender" means a
polyactive hydrogen compound having a functionality of about 2 to
4, more preferably 2 to 3, and most preferably about 2 and
generally having a molecular weight of about 30 to 2000, preferably
30 to 1000. Preferred chain extenders are polyfunctional alcohols,
amines, or carboxylic acid hydrazides. Most preferred chain
extenders are polyfunctional amines and carboxylic acid
hydrazides.
Useful polyamines include: ethylenediamine; 1,6-diaminohexane;
piperazine; tris(2-aminoethyl)amine; and amine terminated
polyethers such as JEFFAMINE D230 and JEFFAMINE D400, from the
Huntsman Corporation, Salt Lake City, Utah., USA.
Useful carboxylic acid hydrazides include adipic acid dihydrazide
and oxalic acid dihydrazide. Particularly useful polyfunctional
alcohols include alkylene diols having 2 to 24 carbon atoms such as
ethylene glycol; 1,4-butane diol; and 1,8-octane diol. Useful
polythiols include 1,2-ethanedithiol; 1,4-butanedithiol;
2,2'-oxytris(ethane thiol) and di- and tri-mercaptopropionate
esters of poly(oxyethylene) diols and triols. Water is also useful
as a chain extender as it reacts with isocyanate to form an
unstable carbamic acid, which loses carbon dioxide to liberate an
amine. This amine is then available to react with another
isocyanate.
When the prepolymer has a functionality of 2 or less and the chain
extender is difunctional, the ratio of isocyanate to active
hydrogen in the chain extension step is preferably from about 0.6:1
to 1.2:1, more preferably from 0.75:1 to 1:1 and most preferably
from 0.80:1 to 1:1 (except when water is used as the sole chain
extender, in which case water can be present in large molar
excess). When the prepolymer has a functionality higher than 2, due
to the use of polyols or polyisocyanates with a functionality
greater than 2, the ratio of isocyanate to active hydrogen present
in the chain extender should be proportionately adjusted downward
to prevent gelation and keep the molecular weight of the
polyurethane polymer formed in an appropriate range to provide cold
seal performance. Also, when the prepolymer has a functionality of
2 or less, some higher functionality chain extender can be used,
e.g., a minor amount of trifunctional amine.
The dispersions of the present invention are in water or
alcohol-water with relatively high concentrations of a lower
alcohol (typically more than 20:80 w/w alcohol to water). In this
environment, endcapping of the isocyanate functional prepolymer may
occur as the isocyanate reacts with the alcohol solvent. Therefore,
use of a polyfunctional amine as the chain extender is preferred
because amines are much more reactive toward isocyanate than the
lower alcohol, giving better control of molecular weight. For use
in skin or hair contact applications where irritation and/or
sensitization is a concern, the most preferred ratio of isocyanate
equivalents to amine equivalents is about 1:0.60 to 1:0.99 in order
to ensure that little to no residual free amine remains in the
final dispersion.
The solvent used as the dispersing medium is selected from the
group consisting of a lower alcohol (C.sub.1 to C.sub.4 branched or
straight chain aliphatic alcohol), water, and mixtures thereof. The
preferred lower alcohols are ethanol, n-propanol, and 2-propanol
(IPA). The most preferred solvents are water, IPA, ethanol, and
mixtures thereof. Preferably the alcohol to water ratio is 20:80 to
90:10 w/w and more preferably the ratio is 70:30 to 85:15. In
general, higher amounts of alcohol will result in a dispersion that
exhibits faster dry times.
The solvent system may also comprise additional solvents. For
example, other rapid evaporating solvents may be used, such as
hexamethyldisiloxane (HMDS); cyclic silicones (D.sub.4 and
D.sub.5); C.sub.4 -C.sub.10 alkanes including isoparafins such as
Permethyl 97A and Isopar C; acetone; hydrofluoroethers (HFEs) and
the like. Certain HFEs, such as HFE 7100, have the added benefit in
certain applications. When it is added to hydro-alcohol mixtures in
levels above about 15 to 25% by weight, the composition becomes
non-flammable.
In one embodiment, the reaction that forms the polyurethane polymer
can be stopped by using chain termination species. These species
stop the growing polymer chain thereby controlling the molecular
weight and the physical properties of the polymer. In one
embodiment, a diamine chain extender is used in excess. The excess
diamine functions as a chain terminator. Another useful chain
terminating agent is 2-amino-2-methyl-1-propanol (AMP), used in
about 0.1 to 2.0 parts, based on the total weight of the
polyurethane polymer. Monofunctional amines or alcohols are useful
as chain terminators. An example of a preferred monofunctional
alcohol is ethanol, which can further function as part of the
dispersing medium. Chain termination may occur during prepolymer
formation, before or after chain extension, or before or after
dispersing in solvent mixture. In the present preferred method, an
amine chain terminator is mixed with the chain extender and added
to the solvent prior to adding the prepolymer.
Preparation of the Dispersion
The dispersions of the present invention may be prepared in any
number of methods. In a first method, the prepolymer can be added
to the solvent as 100% solids or diluted first with a different
solvent that may or may not be removed later. If the solvent is to
be removed, it is preferably more volatile than either water or the
lower alcohol. In another method, the prepolymer can be dispersed
in part of or in all of the solvent mixture or in a portion of the
solvent mixture with subsequent addition of additional solvents.
Any additional solvent added after dispersion is preferably added
slowly in order to ensure the dispersion maintains stability. In
yet another method, the prepolymer and/or dispersion solvent may be
heated or cooled. In yet another method, the prepolymer may be
dispersed in the solvent prior to, simultaneously with, or after
the chain extension and chain termination has been added to the
solvent mixture.
The preferred dispersion method involves heating the prepolymer to
temperatures of about 45.degree. C. to 80.degree. C. to reduce its
viscosity. The heated prepolymer is added to a rapidly stirring
high shear mixing apparatus, such as a homogenizer, containing the
solvent. Thereafter, the amine, a chain extender, is added at a
predetermined rate. Alternatively, for certain formulations, the
amine can be added to the solvent mixture first and the heated
prepolymer added to the rapidly mixing solvent mixture.
For an alcohol-water system, the level of lower alcohol is
preferably at least 20% by weight, more preferably at least 40%,
even more preferably at least 60%, and most preferably at least 70%
by weight. The level of lower alcohol preferably is not more than
90% and more preferably not more than 85%. As used herein, "percent
solids" is defined as the percentage of non-volatile components
present in the dispersion. For cold seal applications where a
uniform continuous 10 to 50 micron coating is desired, the percent
solids should be above about 15%, preferably greater than 25%, and
most preferably greater than about 40% by weight. For other
applications where a lighter or discontinuous coating is desired,
percent solids levels down to 2% and less may be advantageously
used.
In one aspect of the present invention, films can be produced from
the dispersion that have very little adhesion or tack to most
surfaces such as skin, hair, and glass but have comparatively high
adhesion to themselves. When tested according to the test methods
described herein, the ratio of adhesion to self to adhesion to
glass is greater than about 2:1, preferably greater than about 3:1,
more preferably greater than about 5:1 and most preferably greater
than about 10:1. In certain embodiments, the ratio exceeds 20:1 and
even 30:1 although such high ratios may not be required for all
applications. When used in cold seal applications (which requires
very little tack but high self adhesion), the adhesion to glass is
preferably less than about 10 Newtons per decimeter (N/dM), more
preferably less than about 8 N/dM and most preferably less than
about 5 N/dM while the adhesion to self is greater than about 10
N/dM, preferably greater than about 20 N/dM, more preferably
greater than about 25 N/dM and most preferably greater than about
30 N/dM.
We have found that one requirement for producing high self adhesive
coatings is the molecular weight of the polyurethane in the final
dispersion. The preferred weight average molecular weight is about
5000 to 50000, more preferably about 15000 to 35000 and most
preferably about 20000 to 30000. When the molecular weight is too
high, the resulting adhesive has very little self-adhesion. When
the molecular weight is too low, the adhesive tends to have higher
tack or adhesion to other substrates.
The molecular weight of the polymer in the final dispersion can be
controlled in several ways. The first method concerns the alcohol
to water ratio used as the dispersing medium. We have found that
for certain polymers, self-adhesion can be achieved at alcohol to
water ratios in excess of about 75:25 wt/wt, preferably above
80:20, and more preferably at or above about 85:15. While not
wanting to be bound by theory, it is believed that at higher
alcohol to water ratios, more of the isocyanate reacts with the
monofunctional alcohol solvent, thereby limiting the molecular
weight. It is also believed that the higher alcohol ratios result
in better solvation and dissolution of the prepolymer thereby also
increasing the likelihood of reaction of the isocyanate groups with
the monofunctional lower alcohol solvent.
The molecular weight of the prepolymer can also be controlled by
the type of alcohol used as the solvent. Primary alcohols may
result in higher self-adhesion than secondary alcohol solvents such
as isopropanol.
The molecular weight of the prepolymer can be further controlled by
the process of dispersion and the process of adding the chain
extender. At the current time, we believe that dispersing the
prepolymer in the solvent first, followed by amine addition (as the
chain extender) at slower rates, can also improve the level of
self-adhesion. A slow amine addition rate, however, can increase
the level of tack.
The presently preferred method of controlling the level of
self-adhesion is with the use of monofunctional amines added prior
to or during the chain extension step. This method will result in
end capping of some isocyanate groups thereby limiting the
molecular weight. The monofunctional amines generally have the
following structure:
where R.sub.1 and R.sub.2 are independently H or C.sub.1 to
C.sub.22 alkyl; C.sub.6 to C.sub.28 aryl, or C.sub.6 to C.sub.28
aralkyl optionally substituted in available positions by N, O, and
S, including alcohol, tertiary amine, quaternary amine, ketone, and
carboxylic acid substitutions. Preferred monofunctional amines are
those that would have low skin irritation if left unreacted in the
formulation, such as 2-amino-2-methylpropanol or higher alkyl
primary and secondary amines as well primary and secondary
alkanolamines.
The level of ionic stabilizer may also effect self-adhesion. At the
current time, it is believed that higher levels of stabilizer may
result in lower self-adhesion.
The formulations of the present invention may also include
plasticizers that can be added either to the prepolymer directly or
can be added to the solvent mixture. The use of plasticizers may
allow for the use of less solvent, and therefore produce more
rapidly drying films. Where plasticizers are used, the base
prepolymer should be formulated to ensure the plasticized adhesive
has sufficient tensile strength. This could require the use of
lower molecular weight polyols (lower NCO equivalent weight
prepolymers). Preferred plasticizers are cosmetically acceptable
emollients such as those disclosed in U.S. Pat. No. 5,951,993 at
column, 17 line 35 to column 21, line 6.
Other compounds may be added to enhance or obtain particular
properties, provided they do not interfere with the coating, and
film forming properties. The dispersion may contain defoaming
agents. Particularly useful defoaming agents include, e.g.,
Surfynol.TM. DF 110L (a high molecular weight acetylenic glycol
nonionic surfactant available from Air Products & Chemicals,
Inc.), SWS-211 (a silicone additive available from Wacker Silicone
Corp), Dehydran.TM. 1620 (a modified polyol/polysiloxane adduct
available from Henkel Corp.), Additive 65 (a silicone additive
available from Dow Corning).
The dispersion may also contain flow and leveling agents such as
Igepal.TM. CO-630 (an ethoxylated nonylphenol nonionic surfactant
available from Rhone-Poulenc Surfactant & Specialty Div.),
FLUORAD FC-171 (a nonionic surfactant available from 3M Company),
FLUORAD FC-430 (a nonionic surfactant available from 3M Company),
and Rexol.TM. 25/9 (an alkyl phenol ethoxylate nonionic surfactant
available from Hart Chemical Ltd). Optionally, the dispersion may
contain rheology modifiers such as the associative thickeners
Acrysol.TM. RM-825, Acrysol TT-935 all available from Rohm and Haas
company.
To increase the service life of the coatings generated from these
dispersions, especially in outdoor applications, photostabilizers
can be added. Useful photostabilizers include Tinuvin.TM. 400, (a
hindered amine light stabilizer), Tinuvin 292 (a hindered amine
light stabilizer), both commercially available from Ciba-Geigy Ltd.
Also, antioxidants, such as IRGANOX 245 available from Ciba-Geigy
Ltd., and Naugard 445, a 4,4'-bis (.alpha.,.alpha.dimethylbenzyl)
diphenylamine, available from Uniroyl Chemicals can be added. For
applications subjected to ultraviolet light (UV) degradation, at
least about 0.1 parts by weight of the UV light stabilizer per 100
parts by weight polyurethane dispersion can be used to inhibit and
retard the yellowing and photo degradation. Typically about 0.1 to
10 parts, preferably about 1 to about 10 parts are used per 100
parts of the polyurethane dispersion.
EXAMPLES
The following examples further illustrate various specific
features, advantages, and other details of the invention. The
particular materials and amounts recited in these examples, as well
as other conditions and details, should not be construed in a
manner that would unduly limit the scope of this invention.
Percentages given are by weight, unless otherwise specified.
Test Methods
The tack of the inventive adhesives was qualitatively assessed by a
"finger appeal" test involving a light touch and short contact
time, and assigned a value of 1 through 5, where 1=tack free,
1.25=very, very, low tack, 1.5=very low tack, 2=low tack,
2.5=low-to-medium tack, 3=medium tack, 3.5=medium-to-high tack,
4=high tack, and 5=very high tack. On this scale, SCOTCH MAGIC
transparent tape from Minnesota Mining and Manufacturing Co. (3M),
St. Paul, Minn., USA has a rating of 5.
A 180.degree. Peel Adhesion is a measure of the force required to
remove an adhesive coated, flexible facestock from a substrate
after a specified period of dwell and at a specific angle and
removal rate. It was determined in accordance with
Pressure-Sensitive Tape Council test PSTC #1. In our testing, the
face stock is a 0.0015 inch (38 micron) polyester film, the dwell
time is one minute (unless otherwise noted), and the pull rate was
12 inches (30.5 cm) per minute. For adhesion to glass, a 1/2 inch
(1.3 cm) by 6 inch (15 cm) strip of tape is placed on a glass plate
freshly cleaned with methyl ethyl ketone. The glass plate is
secured onto the platform of an I-Mass Peel Tester from
Instrumentors, Inc., Strongsville, Ohio., USA. The strip is pressed
onto the substrate by rolling twice (once in each opposite
direction) with a 4.5 lb (2 kg) rubber roller. After a one (1)
minute dwell, one end of the tape is doubled back until it is
almost touching itself, making an angle of 180.degree. with the
glass plate, and clamped into the jaws of the I-Mass Tester. The
average force required to separate the adhesive coated tape from
the glass plate is recorded as the adhesion to glass. This force
measurement is obtained in units of ounces per half inch and is
converted to Newtons per decimeter (N/dm) by multiplying by 2.189
conversion factor.
A sample's adhesion to self is measured by modifying the standard
PSTC #1 test by laminating the 1/2 inch by 6 inch tape to the
adhesive coated side of a 3/4 inch (1.9 cm) by 8 inch (20 cm) strip
of the same tape with two passes of the 2 kg rubber roller. After a
one (1) minute dwell, the 3/4 inch tape is adhered to the platform
of the I-Mass Peel Tester with 3M SCOTCH double coated tape, and
the 1/2 inch taped peeled from it at 180.degree..
Preparation of the Sulfopolyester Diol Precursors
Sulfopolyester Diol A
A mixture of dimethyl 5-sodiosulfoisophthalate (DMSSIP, 337.3 g,
1.14 mol, from E. I. DuPont de Nemours, Wilmington, Del., USA),
diethylene glycol (DEG, 424 g, 3.99 mol, from Aldrich Chemical Co.,
Milwaukee, Wis., USA), and zinc acetate, (0.82 g, from Aldrich) was
heated to about 180.degree. C. and the methanol by-product was
distilled from the reaction mixture. After 4.5 hours NMR analysis
of the reaction product showed that less than about 1% residual
methyl ester was present in the reaction product.
Dibutyltin dilaurate catalyst (1.51 g, 2.4 mmol, from Alfa Chemical
Co., Ward Hill, Mass., USA) was added to the above reaction
product, the temperature held at about 180.degree. C., and
epsilon-caprolactone (650 g, 5.7 mol, from Aldrich) was added
portionwise over about a 30 minute period. When addition was
complete, the reaction mixture was held at about 180.degree. C. for
4 hours. The product is designated as sulfopolyester diol A
Determination of the hydroxyl equivalent weight of the reaction
product was done as follows. A 5.12 g sample of the product mixture
was dissolved in 20 mL of methyl ethyl ketone (MEK). Isophorone
disocyanate (3.13 g, 14.1 mmol, from Aldrich) and dibutyltin
dilaurate (0.02 g) were added. The solution was heated for about 4
hours at about 80.degree. C. The solution was cooled to room
temperature. A solution of dibutyl amine (4 milliliter (mL) of a
1.72 molar solution in MEK) was added, and the solution stirred for
15 minutes. Then, 20 mL of methanol and 4 to 5 drops of Bromphenol
Blue indicator were added, and the solution titrated to a yellow
endpoint with 2.17 mL of a 1.0 molar hydrochloric acid solution in
water. This corresponds to a hydroxyl equivalent weight of about
218 (theoretical hydroxyl equivalent weight for sulfopolyester diol
A is 235).
Sulfopolyester Diol B
A reactor equipped with a mechanical stirrer, nitrogen purge, and
distillation apparatus was charged with
dimethyl-5-sodiosulfoisophthalate (700 grams, 4.73 equivalents,
from Du Pont, Wilmington, Del., USA), 400 molecular weight
polyethylene glycol (1947 grams, 9.735 equivalents, from Union
Carbide Corp.; Danbury, Conn., USA), and 425 molecular weight
polypropylene glycol (1947 grams, 9.184 equivalents, from Arco
Chemical Co.; Newton Square, Pa., USA). The reactor was heated to
345.degree. F. (174.degree. C.) and vacuum was applied on the
reactor and held for about 1.5 hours. The vacuum was broken with
nitrogen. Titanium butoxide (3.6 grams) was added and the mixture
was heated to 430.degree. F. (220.degree. C.) and held for 3 hours
while collecting methanol. The temperature was then reduced to
345.degree. F (174.degree. C.) and vacuum was applied to the
reaction mixture for one hour. The contents were subsequently
cooled to 200.degree. F. (93.degree. C.) under nitrogen and drained
to yield a clear, colorless liquid polyol. The measured OH
equivalent weight of this polyol is 313 g/mole OH (theoretical OH
of 305). The theoretical sulfonate equivalent weight of the polyol
mixture is 1879 g polymer/mole sulfonate.
Sulfopolyester Diol C
A 5-liter reaction vessel was charged with 4100 g polyethylene
glycol-600 (13.67 equivalents) and 505.67 g
dimethyl-5-sodiosulfoisophthalate (3.42 equivalents). The materials
were dried under full vacuum at 100.degree. C. for 1 hour.
Tetrabutyl titanate (0.08 wt %) was subsequently added and the
reaction was heated at 220.degree. C. until approximately 85% of
the theoretical methanol had been removed. The reaction temperature
was reduced to 170.degree. C. and held under vacuum for 1 hour
resulting in a clear, light-yellow material. Calculated hydroxyl
equivalent weight was 428, calculated sulfonate equivalent weight
was 2632.
Examples 1 to 3
Examples 1 to 3 showed how varying the ethanol-water ratio can
change the molecular weight, and hence the peel adhesion values, of
the polyurethane dispersion.
Into a one-liter reactor was charged the following components to
make a 600 gram batch: 120.6 g (1.09 NCO equivalents) isophorone
diisocyanate; 147.6 g (0.089 OH equivalents) KRATON L-2203
hydrogenated polybutadiene diol (OH equivalent weight 1660) from
Shell Chemical Co., Houston, Tex., USA; 296.4 g (0.291 OH
equivalents) TERATHANE 2000 polytetramethylene oxide diol (OH
equivalent weight 1020) from E. I. du Pont Co., Wilmington, Del.,
USA; 6 g (0.05 OH equivalents) SURFYNOL 104 surfactant, a diol,
from Air Products, Lehigh Valley, Pa., USA (OH equivalent weight
113.2); and 24 g (0.110 equivalents) of sulfopolyester diol A
prepared above. This hazy mixture was heated with stirring under
nitrogen to about 80.degree. C and 0.5 g of dibutyl tin dilaurate
catalyst was added. An exotherm to about 90.5.degree. C. occurred,
and the reaction was continued with stirring for about 2.5 hours at
80.+-.5.degree. C.
Then, 60 g aliquots (theoretically containing 58.5 milliequivalents
of residual NCO) of the resulting product were added to 200 mL
glass jars containing 1.48 g (49 milliequivalents of amine)
ethylene diamine chain extender in 85.5 g ethanol solvent and 4.5 g
water solvent (95:5 ratio, Example 1) or 76.5 g ethanol and 13.5 g
water (85:15 ratio, Example 2) or 67.5 g ethanol and 22.5 g water
(75:25 ratio, Example 3). Stirring at moderate speed yielded a
milky white 40 wt % solids dispersion for all. The resulting
dispersions were coated onto a 0.0015 inch (38 micron) thick
polyester film at a wet coating thickness of about 0.005 inch (127
microns), dried in a 70.degree. C. forced air oven for 10 minutes
yielding clear films, then conditioned overnight under constant
temperature (about 22.degree. C.) and humidity (about 50% relative
humidity). The samples were tested using the test methods described
above. Results are shown in Table I below.
TABLE I Test data for Examples 1 through 3 EtOH:Water Peel from
Glass Peel from Self Example Ratio Tack (N/dM) (N/dM) 1 95:5 2 121
108 2 85:15 1.5 2 88 3 75:25 1.5 0.7 71
During peel testing of Example 1, it was noted that the sample
showed cohesive failure. As stated, cohesive strength is a measure
of the adhesion of the film to itself. Thus, Example 1 is not a
particularly useful embodiment in cold seal adhesive application.
Examples 2 and 3, however, showed low adhesion to glass but rather
good adhesion to self making them more useful as cold seal
adhesives.
Examples 4 to 8
Examples 4 to 8 showed how varying weight ratio of the chain
extender to the chain terminator can affect the molecular weight of
the polyurethane dispersion.
Following the procedure used in Example 1, 78.8 g (47.5 milliequiv
OH) KRATON L-2203 diol, 157.6 g (154.5 milliequiv OH) TERATHANE
2000 diol, 12.0 g (40 milliequiv OH) sulfopolyester diol B made
above, and 51.5 g (464.3 milliequiv NCO) isophorone diisocyanate
were charged into a 500 mL reactor and heated with stirring to
about 80.degree. C. under nitrogen. About two (2) drops of dioctyl
tin dilaurate were added and an exotherm to about 87.degree. C. was
noted. After reacting for about 21/2 hours, the mixture was cooled
slightly and 30 g aliquots (with 22.2 milliequiv theoretical
unreacted NCO) were charged into 100 mL jars containing 45 g of
85:15 ethanol to water solutions of ethylene diamine (EDA, chain
extender) and 2-amino-2-methyl-1-propanol (AMP, chain terminator)
in various ratio. These mixtures were homogenized with an Omni
Macro Homogenizer from Omni International, Marietta, Ga., USA.
Coating and testing was done as described in Example 1, with
results shown in Table II below.
TABLE II Formulations and Test Data for Examples 4 through 8 Amount
of Amount of EDA grams AMP grams Peel from Peel from Ex. (mequiv)
(mequiv) Tack Glass (N/dM) Self (N/dM) 4 0.70 (23.3) 0 (0) 1.25 5
70 5 0.63 (21.0) 0.21 (2.3) 1.25 19 46 6 0.56 (1.87) 0.41 (4.6) 1.5
24 21 7 0.49 (16.3) 0.62 (7.0) 2 34 35 8 0.35 (11.7) 1.03 (11.6) 3
89 86
During testing, Example 8 showed cohesive failure.
Examples 9 and 10
Following the procedure used in Example 1, 46.7 g (28.1 milliequiv
OH) KRATON L-2203 diol, 93.3 g (91.5 milliequiv OH) TERATHANE 2000
diol, 20.0 g (66.7 milliequiv OH) sulfopolyester diol B made above,
and 40 g (360.4 milliequiv NCO) isophorone diisocyanate were
charged into a 500 mL reactor and heated with stirring to about
80.degree. C. under nitrogen. One drop of dioctyl tin dilaurate was
added and an exotherm to about 82.degree. C. was noted. After
reacting for about 2 hours, the mixture was cooled slightly and 30
g aliquots (with 26.1 milliequiv theoretical unreacted NCO) were
charged into 100 mL jars containing 45 g of 85:15 ethanol-water
solution of 0.81 g or 0.65 g (27 milliequiv) EDA and 0.48 g (5.4
milliequiv) AMP. These mixtures were homogenized with an Omni Macro
Homogenizer.
Comparative Examples A and B
Comparative Examples A and B were prepared according to Examples 9
and 10 above respectively, except that the resulting polyurethane
dispersion was dispersed in 100% water. Comparative Examples A and
B formed cheesy precipitates and could not be coated. ND means "not
determined."
TABLE III Formulations and Test Data EtOH:Water EDA AMP Peel from
Peel from Ex. Ratio (grams) (grams) Tack Glass (N/dM) Self (N/dM)
Comp. A 0:100 0.81 0 ND ND ND Comp. B 0:100 0.65 0.48 ND ND ND 9
85:15 0.81 0 1.25 19 100 10 85:15 0.65 0.48 1.25 13 33
Examples 11 to 13
Following the procedure used in Example 1, 36.8 g (22.2 milliequiv
OH) KRATON L-2203 diol, 73.6 g (72.2 milliequiv OH) TERATHANE 2000
diol, 40.0 g (133.3 milliequiv OH) sulfopolyester diol B, and 49.6
g (446.8 milliequiv NCO) isophorone diisocyanate were charged into
a 500 mL reactor and heated with stirring to about 80.degree. C.
under nitrogen. One (1) drop of dioctyl tin dilaurate was added and
an exotherm to about 85.degree. C. was noted. After reacting for
about 2 hours, the mixture was cooled slightly and 30 g aliquots
(with 32.9 milliequiv theoretical unreacted NCO) were charged into
100 mL jars containing 45 g of either water or 85:15 ethanol-water
solution of 1.00 g (33 milliequiv) EDA or 0.80 g (26.7 milliequiv)
EDA and 0.60 g (6.7 milliequiv) AMP. These mixtures were
homogenized with an Omni Macro Homogenizer. The EDA/AMP/100% water
solution (Example 11) was fairly well dispersed and formed a
rough/hazy coating. Coating and testing on the others was done as
described in Example 1. The results are shown in Table IV below,
with ND for "not determined."
Comparative Example C
Comparative Example C was prepared similar to Example 12 and
dispersed in 100% water solvent system. Comparative C contained the
EDA chain extender but no chain terminator. It formed a cheesy
precipitate and could not be coated.
TABLE IV Formulations and Test Data EtOH:Water EDA AMP Peel from
Peel from Ex. Ratio (grams) (grams) Tack Glass (N/dM) Self (N/dM)
Comp. C 0:100 1.00 0 ND ND ND 11 0:100 0.80 0.60 1.5 0.2 2 12 85:15
1.00 0 1.25 8 0.6 13 85:15 0.80 0.60 1.5 23 2
Examples 14 to 17
Following the procedure used in Example 1, 157.84 g (95.1
milliequiv OH) KRATON L-2203 diol, 315.45 g (309.3 milliequiv OH)
TERATHANE 2000 diol, 24.39 g (81.3 milliequiv OH) sulfopolyester
diol B, and 103.4 g (931.5 milliequiv NCO) isophorone diisocyanate
were charged into a 500 mL reactor and heated with stirring to
about 55.degree. C. under nitrogen. Three (3) drops of dioctyl tin
dilaurate were added and a slight exotherm was noted. The
temperature was raised to about 80.degree. C. and held there for
about 2 hours. The mixture was cooled slightly and 90 g aliquots
(with 67.2 milliequiv theoretical unreacted NCO) were charged into
500 mL jars containing 135 g of 85:15 ethanol-water solvent system
containing EDA and AMP in various ratio. These mixtures were
homogenized with an Omni Macro Homogenizer. Coating and testing was
done as described in Example 1, with results shown in Table V
below.
TABLE V Formulations and Test Data for Examples 14 through 17 EDA
AMP Peel from grams grams Glass Peel from Self Ex. (mequiv)
(mequiv) Tack (N/dM) (N/dM) 14 1.99 (66.3) 0 (0) 1.25 5 39 15 1.88
(62.7) 0.31 (3.5) 1.25 10.5 delamination 16 1.78 (59.3) 0.62 (7.0)
1.5 16 52 17 1.57 (52.3) 1.24 (13.9) 2 31 19
Examples 18 to 21
Following the procedure used in Example 1, 52.55 g (31.7 milliequiv
OH) KRATON L-2203 diol, 105.09 g (105.1 milliequiv OH) polyethylene
glycol 2000 diol from Aldrich Chemical Co., 8 g (36.7 milliequiv
OH) sulfopolyester diol B, and 34.34 g (30.9 milliequiv NCO)
isophorone diisocyanate were charged into a 500 mL reactor and
heated with stirring to 80.degree. C. under nitrogen. Two (2) drops
of dioctyl tin dilaurate were added and an exotherm to 86.degree.
C. was noted. The reaction was continued for about 2 hours, then
the mixture was cooled slightly and 30 g aliquots (with 20.4
milliequiv theoretical unreacted NCO) were charged into 200 mL jars
containing 45 g of either water or 85:15 ethanol-water solvent
systems containing EDA and AMP in various ratio. These mixtures
were homogenized with an Omni Macro Homogenizer, giving good
dispersions in all cases. Coatings were clear and tacky when
removed from the oven, but slightly hazy and tack free with no
adhesion to glass or self after conditioning overnight.
Examples 22 to 24
Following the procedure used in Example 1, 78.85 g (47.5 milliequiv
OH) KRATON L-2203 diol, 157.6 g (157.6 milliequiv OH) polypropylene
glycol 2000 diol from EM Science, Gibbstown, N.J., USA, 12.2 g
(40.7 milliequiv OH) sulfopolyester diol B, and 52.25 g (470.7
milliequiv NCO) isophorone diisocyanate were charged into a 500 mL
reactor and heated with stirring to 80.degree. C. under nitrogen.
Two (2) drops of dioctyl tin dilaurate were added and an exotherm
to 81.degree. C. was noted. After reacting for 2 hours, the mixture
was cooled slightly and 30 g aliquots (with 22.4 milliequiv
theoretical unreacted NCO) were charged into 100 mL jars containing
45 g of 85:15 ethanol-water solvent mixtures containing EDA and AMP
in various ratio. These mixtures were homogenized with an Omni
Macro Homogenizer. Coating and testing was done as described in
Example 1, with results shown in Table VI below.
TABLE VI Formulations and Test Data for Examples 22 through 24 EDA
AMP Peel from grams grams Glass Peel from Self Ex. (mequiv)
(mequiv) Tack (N/dM) (N/dM) 22 0.66 (22.0) 0 (0) 1.25 18 165 23
0.63 (21.0) 0.10 (1.1) 1.5 23 Delamination 24 0.59 (1.97) 0.21
(2.4) 1.5 40 Delamination
Examples 25 to 28
Following the procedure used in Example 1, 25 g (15.1 milliequiv
OH) KRATON L-2203 diol, 50 g (40.5 milliequiv OH) TEXOX 5WL-1400
2470 molecular weight 75/25 ethylene glycol/propylene glycol random
copolymer diol from Texaco Chemical, Houston, Tex., USA, 4 g (13.3
milliequiv OH) sulfopolyester diol B, and 15.3 g (137.8 milliequiv
NCO) isophorone diisocyanate were charged into a 500 mL reactor and
heated with stirring to about 80.degree. C. under nitrogen. One (1)
drop of dioctyl tin dilaurate was added and the reaction continued
for about 2 hours. The mixture was cooled slightly and 20 g
aliquots (with 14.7 milliequiv theoretical unreacted NCO) were
charged into 100 mL jars containing 30 g of either water or 85:15
ethanol-water solvent mixture containing 0.42 g (14 milliequiv) EDA
or 0.37 g (12.3 milliequiv) EDA and 0.13 g (1.5 milliequiv) AMP.
These mixtures were homogenized with an Omni Macro Homogenizer. The
100% water dispersions (Examples 25 and 26) were very viscous.
Coating and testing was done as described in Example 1, with
results shown in Table VII below.
TABLE VII Formulations and Test Data for Examples 25 through 28
EtOH:Water EDA AMP Peel from Peel from Ex. Ratio (grams) (grams)
Tack Glass (N/dM) Self (N/dM) 25 0:100 0.42 0 2 4 64 26 0:100 0.37
0.13 1.5 9 130 27 85:15 0.42 0 3 27 55 28 85:15 0.37 0.13 4 37
cohesive 27
Example 26 showed cohesive failure during the peel from self test.
Example 27 showed partial delamination during the peel from self
test. Example 28 showed cohesive failure during both peel
tests.
Examples 29 to 31
Following the procedure used in Example 1, 26.4 g (15.9 milliequiv
OH) KRATON L-2203 diol, 36.5 g (182.5 milliequiv OH) 400 molecular
weight polyethylene glycol diol from Aldrich Chemical, 4.8 g (16.0
milliequiv OH) sulfopolyester diol B, and 31.1 g (280.2 milliequiv
NCO) isophorone diisocyanate were charged into a 500 mL reactor and
heated with stirring to about 80.degree. C. under nitrogen. One (1)
drop of dioctyl tin dilaurate was added and an exotherm to about
97.degree. C. was noted. The reaction continued for about 1 hour
during which time the viscosity increased.
The mixture was cooled slightly and 20 g aliquots (with 13.3
milliequiv theoretical unreacted NCO) of the thick paste were
charged into 100 mL jars containing 30 g of either water or 85:15
ethanol-water solution of 1.86 g (62.0 milliequiv) EDA or 1.66 g
(55.3 milliequiv) EDA and 0.58 g (6.5 milliequiv) AMP. These
mixtures were homogenized with an Omni Macro Homogenizer. The thick
paste could not be dispersed in water, but could be dispersed with
difficulty in ethanol-water and yielded grainy coatings. Coating
and testing was done as described in Example 1, with results shown
in Table VIII below.
TABLE VIII Formulation and Test Data for Examples 29 through 31
EtOH:Water EDA AMP Peel from Peel from Ex. Ratio (grams) (grams)
Tack Glass (N/dM) Self (N/dM) 29 0/100 1.86 0 ND ND ND 30 85/15
1.86 0 3 4 9 31 85/15 1.66 0.58 4 20 33
Examples 32 to 37
Following the procedure used in Example 1, 40.4 g (24.3 milliequiv
OH) KRATON L-2203 diol, 80.7 g (65.3 milliequiv OH) TEXOX WL-1400
2470 molecular weight 75/25 ethylene glycol/propylene glycol random
copolymer diol from Texaco Chemical, 6 g (13.3 milliequiv OH)
sulfopolyester diol C, and 23.1 g (208.1 milliequiv NCO) isophorone
diisocyanate were charged into a 500 mL reactor and heated with
stirring to about 80.degree. C. under nitrogen. One (1) drop of
dioctyl tin dilaurate was added and the reaction exothermed to
about 82.degree. C.
After reacting for about 2 hours, the mixture was cooled slightly
and 20 g aliquots (with 14.0 milliequiv theoretical unreacted NCO)
were charged into 100 mL jars containing 30 g of either water or
85:15 ethanol-water solution of 0.40 or 0.41 g (13.3 or 13.7
milliequiv, respectively) EDA or 13.9 g (13.9 milliequiv) JEFFAMINE
ED2001 2000 molecular weight polyethylene oxide diamine from
Huntsman Corporation, Salt Lake City, Utah., USA. TWEEN 40 and
STANDAPOL ES2 surfactants were added at 2 wt. % actives to selected
dispersions. These mixtures were homogenized with an Omni Macro
Homogenizer. All samples had good dispersions. Coating and testing
was done as described in Example 1, with results shown in Table IX
below.
TABLE IX Formulations and Test Data for Examples 32 through 37
EtOH:Water Diamine Peel from Peel from Ex. Ratio (grams) Surfactant
Tack Glass (N/dM) Self (N/dM) 32 0:100 0.40 EDA None 2 16 56 33
0:100 0.40 EDA Tween 40 2.5 15 50 34 0:100 0.40 EDA Standapol 2 10
43 ES2 35 0:100 13.9 None 3.5 30 25 Jeffamine 36 85:15 0.40 EDA
None 4 28 18 37 85:15 0.41 EDA None 4 5 3
Examples 38 to 41
Following the procedure used in Example 1, 78.8 g (47.5 milliequiv
OH) KRATON L-2203 diol, 157.5 g (154 milliequiv OH) TERATHANE 2000
diol (T-2000), 12.2 g (40.7 milliequiv OH) sulfopolyester diol B,
and 51.6 g (464 milliequiv NCO) isophorone diisocyanate were
charged into a 500 mL reactor and heated with stirring to about
60.degree. C. under nitrogen. 3 drops of dibutyl tin dilaurate was
added and an exotherm to about 77.degree. C. was noted. The
reaction temperature was increased to 80.degree. C. and held there
for about 2 hours.
The mixture was cooled slightly and 50 g aliquots (with 40.0
milliequiv theoretical unreacted NCO) of the prepolymer were
charged with stirring into 200 mL jars containing 60 g of a 85/15
ethanol/water mixture. A mixture of 1.04 g (34.7 milliequiv) EDA
and with 1.9 mequiv of various amine terminators in 15 g of 85:15
ethanol-water were charged in one portion after the prepolymer is
well dispersed. Specific amine terminators used were 0.17 g
2-amino-2-methyl-1-propanol (Example 38), 0.36 g dodecyl amine
(Example 39), 0.52 g octadecyl amine (Example 40), and 0.77 g
didodecyl amine (Example 41). Coating and testing was done as
described in Example 1, with results shown in Table X below.
TABLE X Formulations and Test Data for Examples 38 through 41 Peel
from Glass Peel from Self Ex. Terminator Tack (N/dM) (N/dM) 38 AMP
1.5 1.3 22.5 39 C12 amine 1.5 0.9 18.2 40 C18 amine 1.5 1.8 32.8 41
di-C12 amine 1.5 4.7 41.2
Examples 42 to 45
Following the procedure used in Examples 38 through 41, 77.0 g
(76.9 milliequiv OH) PRIPLAST 3197, a 2000 molecular weight
polyester diol of dimer diacid and dimer diol from Uniqema, 154.0 g
(151 milliequiv OH) TERATHANE 2000 diol, 12.2 g (40.7 milliequiv
OH) sulfopolyester diol B, and 56.8 g (511 milliequiv NCO)
isophorone diisocyanate were reacted and dispersed in the identical
fashion.
TABLE XI Formulations and Test Data for Examples 42 through 45 Peel
from Glass Peel from Self Ex. Terminator Tack (N/dM) (N/dM) 42 AMP
1.5 3.7 62.6 43 C12 amine 2 3.9 67.2 44 C18 amine 1.5 3.9 69.2 45
di-C12 amine 1.5 5.0 47.1
Examples 46 to 49
Following the procedure used in Examples 38 through 41, 78.8 g
(47.5 milliequiv OH) KRATON L2203 diol, 154.0 g (152 milliequiv OH)
2200 molecular weight polypropylene glycol (PPG 2200), 12.2 g (40.7
milliequiv OH) sulfopolyester diol B, and 51.6 g (464 milliequiv
NCO) isophorone diisocyanate were reacted and dispersed in the
identical fashion.
TABLE XII Formulations and Test Data for Examples 46 through 49
Peel from Glass Peel from Self Ex. Terminator Tack (N/dM) (N/dM) 46
AMP 2 21.7 117.3 47 C12 amine 3 19.7 80.8 48 C18 amine 3 20.4 107.3
49 di-C12 amine 3 28.9 121.9
Examples 50 to 55
The prepolymers prepared for Examples 38 through 41 and 46 through
49 (with Terathane 2000 or PPG 2200 respectively) were reacted with
varying amounts of ethylene diamine and aminomethylpropanol as
shown in Table XIII below.
TABLE XIII Formulations and Test Data for Examples 50 through 55
Peel from EDA AMP Glass Peel from Ex. Diol (grams) (grams) Tack
(N/dM) Self (N/dM) 50 T2000 0.98 0.36 1.5 6.8 60.2 51 T2000 1.02
0.30 1 3.3 63.9 52 T2000 1.00 0.23 1.25 4.4 44.4 53 PPG2200 0.97
0.36 4 45.8 108.8 54 PPG2200 0.99 0.23 3 25.4 102.7 55 PPG2200 1.02
0.16 2.5 4.2 72.5
Examples 56 to 59
Following the procedure used in Example 1, 25.6 g (20.5 milliequiv
OH) polybutadiene polyol with an OH equivalent weight of 1250 and
an average functionality greater than 2 sold under the tradename
POLY bd by Elf Atochem, Philadelphia, Pa., 51.4 g (51.4 milliequiv
OH) TERATHANE 2000 diol, 4.2 g (13.4 milliequiv OH) sulfopolyester
diol B, and 18.9 g (170 milliequiv NCO) isophorone diisocyanate
were charged into a 250 mL reactor and heated with stirring to
about 60.degree. C. under nitrogen. Two (2) drops of dioctyl tin
dilaurate was added and an exotherm to about 71.degree. C. was
noted. The reaction temperature was increased to 80.degree. C. and
held there for about 2 hours.
The mixture was cooled slightly and 20 g aliquots (with 16.9
milliequiv theoretical unreacted NCO) of the prepolymer were
charged with stirring into 100 mL jars containing 30 g of a 85/15
ethanol/water mixture containing varying amounts of EDA and AMP.
Coating and testing was done as described in Example 1, with
results shown the table below.
TABLE XIV Formulations and Test Data for Examples 56 through 59 EDA
AMP Peel from Glass Peel from Self Ex. (grams) (grams) Tack (N/dM)
(N/dM) 56 0.35 0.45 gelled ND ND 57 0.3 0.6 gelled ND ND 58 0.25
0.75 2 98.3 174.7 59 0.2 0.9 2 143.0 coh 124.3
Examples 60 to 79
Following the procedure used in Example 1, KRATON L-2203 diol and
TERATHANE 2000 diol were reacted at various ratios with isophorone
diisocyanate (IPDI) and assorted stabilizers including VARIQUAT
K1215 cationic diol from Witco, 600 molecular weight polyethylene
glycol, dimethylol propanic acid (DMPA), sulfopolyester diol B, or
with no additional added stabilizer. The prepolymers were dispersed
into ethanol water containing EDA chain extender and AMP chain
terminator as detailed below. Coating and testing was done as
described in Example 1, with results also shown in Table XV.
TABLE XV Formulations and Test Data for Examples 60 through 79
Prepolymer Dispersion KRATON TERATHANE Stabilizer IPDI
ethanol/water Peel from Peel from Self Ex. (grams) (grams) (grams)
(grams) EDA AMP ratio Tack Glass (N/dM) (N/dM) 60 39.0 76.6 9 g
Variquat 26.3 0.71 0 85/15 1.5 4.4 40.5 61 39.0 76.6 9 g Variquat
26.3 0.64 0.21 85/15 1.5 21.9 60.4 62 39.0 76.6 9 g Variquat 26.3
0.57 0.41 85/15 1.5 6.1 32.0 63 34.0 69.4 15 g PEG 600 20.7 0.84 0
85/15 1.5 5.9 55.4 64 34.0 69.4 15 g PEG 600 20.7 0.76 0.25 85/15
1.5 6.8 24.7 65 34.0 69.4 15 g PEG 600 20.7 0.67 0.5 85/15 1.5 13.8
23.0 66 38.3 76.5 3 g DMPA 32.2 0.87 0.4 85/15 1 0.4 0.9 67 38.3
76.5 3 g DMPA 32.2 0.78 0.66 85/15 1 0.7 1.3 68 38.3 76.5 3 g DMPA
32.2 0.7 0.92 85/15 1 1.1 2.0 69 28.2 55.8 0 16.2 0.59 0.2 100/0
1.25 0.4 1.3 70 28.2 55.8 0 16.2 0.59 0.2 85/15 1.25 0.2 5.0 71
57.3 28.7 0 14 0.38 0 100/0 1 0.0 0.9 72 57.3 28.7 0 14 0.3 0.22
100/0 1 0.2 0.0 73 21.2 21.2 0 7.6 0.33 0.24 100/0 1 0.7 0.9 74
21.2 21.2 0 7.6 0.33 0.24 85/15 1 0.0 0.0 75 8.3 33.2 0 8.5 0.36
0.27 85/15 1 0.0 0.7 76 4.1 37.1 0 8.8 0.38 0.28 85/15 1 0.2 2.8 77
4.1 37.1 0 8.8 0.38 0.28 70/30 1.25 9.2 71.8 78 3.8 34.6 2 g 9.6
0.41 0.31 85/15 1.25 0.0 13.4 Sulfopolyester diol B 79 3.8 34.6 2 g
9.6 0.41 0.31 70/30 1.25 2.2 53.4 Sulfopolyester diol B
Cosmetic Example 1
A body lotion suitable for use as a waterproof sunscreen or insect
repellent with added active ingredients was prepared. An
oil-in-water emulsion was prepared using the specific components
and amounts in weight percent for Phase A and Phase B listed in
Table XVI. Phase A and Phase B were heated to 70.degree. C. with
continuous stirring in separate vessels. Phase B was added to Phase
A and homogenized using a high shear mixer. Cooling to room
temperature with slight agitation yields a moderate viscosity
cream.
TABLE XVI Oil-in-water emulsion for body lotion Component Amount
(weight percent) Phase A Mineral oil 10.0 Isopropyl myristate 2.0
Stearic acid 4.0 Glycerol stearate 3.0 Ceteth-20 1.0 Lanolin oil
0.6 Dispersion from Example 16 2.4 Phase B Deionized water 76.8
Hydroxyethyl cellulose 0.2 Triethanol amine 1.2
Cosmetic Example 2
An oil in water emulsion for mascara was prepared using the
specific components and amounts in weight percent for Phase A and
Phase B listed in Table XVII. Phase A and Phase B were heated to
90.degree. C. with continuous stirring in separate vessels. Phase B
was added to Phase A and homogenized using a high shear mixer.
After cooling, the resulting paste provides a flake-, smudge-, and
water-resistant mascara.
TABLE XVII Oil-in-water emulsion for mascara Component Amount
(weight percent) Phase A Carnuba wax 10.0 Isopropyl myristate 6.0
Stearic acid 5.0 Glycerol stearate 3.0 Dispersion from Example 16
6.0 Black iron oxide pigment 10.0 Phase B Deionized water 57.5
Polyvinylpyrrolidone 1.0 Hydroxyethyl cellulose 0.2 Triethanol
amine 1.3
Cosmetic Example 3
A conditioning shampoo was prepared by charging 35.7 wt. % ammonium
lauryl sulfate (28% solids), 24 wt. % ammonium laureth-2-sulfate
(25% solids), 3 wt. % ethylene glycol distearate, 1 wt. % cocamide
MEA, and 31.2 wt. % deionized water into a vessel. The resulting
mixture was heated to 80.degree. C. with stirring and a mixture
containing 5 wt. % of the dispersion of Example 16 in 5 wt % of
C.sub.12 to C.sub.15 alkyl benzoate was added. After cooling, the
resulting pearly liquid provides a shampoo with good wet
combability after rinsing and fast drying.
Cosmetic Example 4
A clear nail lacquer was made as follows: About 20 parts of a 20%
solids ethanol solution of an acrylate grafted silicone copolymer
available from 3M Corporation, St. Paul, Minn. under the trade
designation VS 80 Silicones Plus copolymer was combined with 1 part
of the dispersion solution from Example 16. This provided a fast
drying clear nail lacquer with good chip resistance and gloss.
Cosmetic Example 5
A shampoo was prepared by charging 36 wt. % ammonium lauryl sulfate
(28% solids), 24 wt. % ammonium laureth-2-sulfate (25% solids), 3
wt. % ethylene glycol distearate, 1 wt. % cocamide MEA, and 6 wt. %
deionized water into a vessel. The resulting mixture was heated to
80.degree. C. with stirring to form a pearly liquid. After cooling,
30 wt. % of the 40% solids dispersion of Example 36 was added to
provide a shampoo that has a foamy lubricious feel when used at 0.5
milliliters on a 2 gram swatch of hair and gives good wet
combability after rinsing and fast drying.
Cosmetic Example 6
A shampoo was prepared by charging 50 wt. % ammonium lauryl sulfate
(28% solids), 11 wt. % disodium cocoamphodiacetate (50% solids),
and 9 wt. % deionized water into a vessel. The resulting mixture
was heated to 80.degree. C. with stirring to form a clear liquid.
After cooling, 30 wt. % of the 40% solids dispersion of Example 36
was added to provide a milky shampoo that has a foamy lubricious
feel when used at 0.5 milliliters on a 2 gram swatch of hair and
gives good wet combability fast drying.
Cosmetic Example 7
A shampoo was prepared by charging 39 wt. % ammonium lauryl sulfate
(28% solids), 11 wt. % cocamidopropyl betaine (35% solids), and 20
wt. % deionized water into a vessel. The resulting mixture was
heated to 80.degree. C. with stirring to form a clear liquid. After
cooling, 30 wt. % of the 40% solids dispersion of Example 36 was
added to provide a shampoo that has a foamy lubricious feel when
used at 0.5 millimeters on a 2 gram swatch of hair and gives good
wet combability after rising and fast drying.
Cosmetic Examples 8 through 19
Using the same ingredients and procedure as Cosmetic Example 7, the
amounts of polymer dispersion and water were varied to give polymer
contents ranging from 0.5 to 11 weight % as shown in the Table
below.
Wt. % Dispersion Example of Ex. 36 Wt % Water % Polymer 8 1.2 48.8
0.5 9 2 48 1 10 5 45 2 11 8 42 3 12 10 40 4 13 12 38 5 14 15 35 6
15 18 32 7 16 20 30 8 17 22 28 9 18 25 25 10 19 28 22 11
All references cited herein are incorporated by reference, in each
reference's entirety.
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